Moving picture compression apparatus and method of controlling operation of same

ABSTRACT

In principle, an I-frame is inserted every 50 frames and other frames are made P-frames. If the maximum amount of data that can be received by a terminal device to which a transmission is to be made is 300 KB, then frames up to a 144 th  frame for which the amount of data after compression will not exceed 300 KB is adopted as a first partitioned moving picture file. Since the 145 th  frame is the leading frame of the next partitioned moving picture file, it is made an I-frame. Frames from the 145 th  frame to a 289 th  frame are made a second partitioned moving picture file, and frames from a 290 th  frame to a 411 th  frame are made a third partitioned moving picture file. Since the leading frame of a partitioned moving picture file represents one complete frame, the moving picture can be reproduced and the number of partitions can be reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus for compressing a moving pictureand to a method of controlling the operation of this apparatus.

2. Description of the Related Art

Services for transmitting moving picture files to a mobile telephone arepresently available, and mobile telephones come in a wide variety ofmodels. Often the amount of data that can be received in a movingpicture file, the format of a moving picture file that can be reproducedand the image display size differ for every model of mobile telephone.In order to so arrange it that a moving picture file can be reproducedby a mobile telephone, there is a technique that decides the amount ofdata that is to be transmitted in a moving picture file (see JapanesePatent Application Laid-Open No. 9-298749), a technique for generating aplurality of items of moving picture data having different bit rates andtransmitting the moving picture data that conforms to the band that isutilizable on the network (see Japanese Patent Application Laid-Open No.11-341488), a technique for transmitting moving picture data in acompressed format that is based upon a request from a user (see JapanesePatent Application Laid-Open No. 2002-232869), and a technique forgenerating moving picture data upon deciding moving picture generatingparameters that conform to the model of a client terminal device bydiscriminating the model of the device (see Japanese Patent ApplicationLaid-Open No. 2004-222124).

Since the amount of data in a moving picture file capable of beingreceived by a mobile terminal such as a mobile telephone often is small,it is required that a moving picture file containing a comparativelylarge amount of data be partitioned in order to for it to be received.Depending upon the format of the moving picture file, however, there areinstances where the file can only be partitioned at the location of aspecific frame. This means there are occasions where a moving picturefile cannot be simply partitioned in such a manner that large amount ofdata can be received by a terminal device.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to so arrange it thata moving picture file can be partitioned in such a manner that a largeamount of data can be received by a terminal device.

In accordance with the present invention, the foregoing object isattained by providing an apparatus for compressing a moving picture,comprising: a compressing device, to which subject-image datarepresenting the image of a subject is input one frame at a time from amoving picture file representing a moving picture composed of a numberof frames of subject images (where each frame is one complete frame of asubject image), for executing complete compression processing such thatthe subject-image data that has been input will become one completeframe of a subject image if the data is subject-image data thatrepresents a subject image from a reference frame (which may be a frameof a prescribed ordinal number from the reference frame or a prescribedframe that is variable), and for executing differential compressionprocessing in such a manner that the subject-image data that has beeninput will indicate differential information relative to the precedingframe if the data is not subject-image data representing a subject imageof a frame of a prescribed ordinal number; an accumulating device foraccumulating amount of data from the reference frame, wherein the amountof data is the amount of subject-image data that has undergone completecompression processing and amount of subject-image data that hasundergone differential compression processing; a determining device fordetermining whether an accumulated value obtained from the accumulatingdevice has exceeded a value calculated from an amount of data receivableby a terminal device to which a moving picture file is to betransmitted; and a control device, responsive to a determination by thedetermination device that the accumulated value obtained from theaccumulating device has exceeded the receivable amount of data, forcontrolling the compressing device in such a manner that completecompression processing is applied to subject-image data representing asubject image of a frame that has exceeded the receivable amount of dataowing to execution of compression processing, and for resetting theaccumulated value from the accumulating device.

The present invention also provides an operation control method suitedto the above-described apparatus for compressing a moving picture.Specifically, the present invention provides a method of controllingoperation of an apparatus for compressing a moving picture, comprisingthe steps of: inputting subject-image data representing the image of asubject one frame at a time from a moving picture file representing amoving picture composed of a number of frames of subject images (whereeach frame is one complete frame of a subject image), executing completecompression processing in such a manner that the subject-image data thathas been input will become one complete frame of a subject image if thedata is subject-image data that represents a subject image of a frame ofa prescribed ordinal number from a reference frame, and executingdifferential compression processing in such a manner that thesubject-image data that has been input will indicate differentialinformation relative to the preceding frame if the data is notsubject-image data representing a subject image of a frame of aprescribed ordinal number; accumulating amount of data from thereference frame, wherein the amount of data is the amount ofsubject-image data that has undergone complete compression processingand amount of subject-image data that has undergone differentialcompression processing; determining whether an obtained accumulatedvalue has exceeded a value calculated from an amount of data receivableby a terminal device to which a moving picture file is to betransmitted; and in response to a determination that the accumulatedvalue obtained has exceeded the receivable amount of data, controllingthe compressing step in such a manner that complete compressionprocessing is applied to subject-image data representing a subject imageof a frame that has exceeded the receivable amount of data owing toexecution of compression processing, and resetting the accumulated valuefrom the accumulating step.

In accordance with the present invention, a subject image of a frame ofa prescribed ordinal number from a reference frame is subjected tocomplete compression processing so as to become one complete frame ofthe subject image. The subject image of a frame other than the frame ofthe prescribed ordinal number is subjected to differential compressionprocessing so as to indicate differential information relative to thepreceding frame. The subject-image data that has been subjected tocomplete compression processing and the subject-image data that has beensubjected to differential compression processing is accumulated. If theaccumulated value exceeds the amount of data receivable by a terminaldevice to which a moving picture file is to be transmitted, thencomplete compression processing is applied to the subject image of theframe that has exceeded the receivable amount of data owing tocompression, and the accumulated value is reset.

In a case where a moving picture file that has thus been subjected tocomplete compression processing or differential compression processingis partitioned, one complete frame of the subject image cannot bereproduced merely by differential information. It is required that themoving picture file be partitioned at a location of the subject imagethat has undergone complete compression processing. According to thepresent invention, when the accumulated value of compressedsubject-image data exceeds the amount of data that can be received by aterminal device to which a moving picture is to be transmitted, completecompression processing is applied to the subject image of the frame thathas exceeded the receivable amount of data. Thus, a partitioned filehaving the maximum amount of data within the receivable amount of datacan be transmitted to the terminal device. The number of partitions of amoving picture file can be reduced.

By way of example, the determining device determines whether theaccumulated value obtained from the accumulating device has exceeded afirst amount of data receivable by a first terminal device to which amoving picture file is to be transmitted, or a second amount of datareceivable by a second terminal device to which a moving picture file isto be transmitted. Further, the control device has a first controldevice, responsive to a determination by the determining device that theaccumulated value has exceeded the first receivable amount of data, forcontrolling the compressing device in such a manner that completecompression processing is applied to subject-image data representing asubject image of a frame that has exceeded the first receivable amountof data owing to execution of compression processing, and for resettingthe accumulated value, and a second control device, responsive to adetermination by the determining device that the accumulated value hasexceeded the second receivable amount of data, for controlling thecompressing device in such a manner that complete compression processingis applied to subject-image data representing a subject image of a framethat has exceeded the first receivable amount of data owing to executionof compression processing, and for resetting the accumulated value.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 illustrate examples of schemes for compressing movingpictures;

FIG. 3 is a block diagram illustrating the electrical configuration ofan apparatus for compressing a moving picture;

FIG. 4 is a flowchart illustrating processing executed by an apparatusfor compressing a moving picture;

FIG. 5 illustrates an example of a scheme for compressing a movingpicture; and

FIG. 6 is a flowchart illustrating processing executed by an apparatusfor compressing a moving picture.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail with reference to the accompanying drawings.

FIG. 1 is a conceptual view of a moving picture that has been compressedby a compression scheme based upon MPEG (Moving Picture Experts Group).

Compression based upon MPEG utilizes both spatial compression andtemporal compression. With MPEG compression, an I-frame (indicated bythe hatching) is generated at a rate of one per plurality of frames. Theother generated frames are P-frames. The I-frame is produced by spatialcompression and is the result of intraframe coding using only datawithin the frame. One complete frame of a subject image can bereproduced using the I frame alone (complete compression processing).The P-frame is produced by temporal (interframe) compression; itindicates differential information relative to the preceding frame(differential compression processing). One complete frame of a subjectimage cannot be reproduced with just a P-frame but it can be reproducedutilizing the subject image of the preceding frame. Consider a movingpicture in which the amount of code of an I-frame is 5 KB, the amount ofcode of a P-frame is 2 KB and there are 412 frames from a 0^(th) frameto a 411^(th) frame. Assume also that a terminal device that transmits amoving picture file representing such a moving picture is capable ofreceiving data up to a maximum amount of 300 KB. Further, assume thatthe I-frame is inserted every 50 frames.

Since the I-frame is inserted every 50 frames, a 0^(th) frame, 50^(th)frame, 100^(th) frame, 150^(th) frame, 200^(th) frame, 250^(th) frame,300^(th) frame, 350^(th) frame and 400^(th) frame are I-frames. Theremaining frames are P-frames. Since an I-frame is 5 KB and a P-frame is2 KB, the amount of data in a moving picture file representing a412-frame moving picture of 0^(th) to 411^(th) frames is a total of 801KB. This cannot be received by the terminal device that is capable ofreceiving data up to a maximum amount of 300 KB. Consequently, themoving picture file is partitioned and the plurality of moving picturefiles thus partitioned are transmitted to the terminal device.

One complete frame of a still image cannot be reproduced with just aP-frame. If a moving picture file in which I- and P-frames are mixed ispartitioned, therefore, an I-frame must be made the initial frame of apartitioned moving picture file. A moving picture file cannot bepartitioned at the location of a P-frame. Therefore, in a case where amoving picture file is transmitted to a terminal device that can receivedata up to the maximum amount of 300 KB, it is necessary to generatefive partitioned moving picture files, namely first, second, third,fourth and fifth partitioned moving picture files, composed of the0^(th) to 99^(th) frames, 100^(th) to 199^(th) frames, 200^(th) to299^(th) frames, 300^(th) to 399^(th) frames and 400^(th) to 411^(th)frames, respectively. These five partitioned moving picture files aretransmitted to the terminal device one after another.

In this embodiment, the number of moving picture files partitioned isreduced. Although partitioned moving picture files are transmitted to aterminal device in response to a request from the user of the terminaldevice, the number of moving picture files partitioned is reduced. Thismeans that the number of times requests are issued from the user can bereduced and that the burden upon the user can be alleviated.

FIG. 2 is a conceptual view of a moving picture that has been compressedby the compression scheme according to this embodiment.

With the compression scheme according to this embodiment, a movingpicture file is partitioned so as to maximize the amount of data thatcan be received by a terminal device to which a transmission is to bemade. The leading frame of a moving picture file that has beenpartitioned is made an I-frame. This serves as the reference frame. In amanner similar to that described above, in principle an I-frame isinserted every 50 frames and P-frames are inserted between I-frames.

Since an I-frame is inserted every 50 frames, the I-frame is inserted as0^(th), 50^(th) and 100^(th) frames and the P-frames are insertedbetween these I-frames. The total amount of data from the 0^(th) frameto the 145^(th) frames is 299 KB, which is calculated as follows:[amount of data (=5 KB) of the 0^(th) frame]+[amount of data (=49×2=92KB) of the 1^(st) to 49^(th) frames]+[amount of data (=5 KB) of the50^(th) frame]+[amount of data (=49×2=92 KB) of the 51^(st) to 99^(th)frames]+[amount of data (=5 KB) of the 110^(th) frame]+[amount of data(=44×2=88 KB) of the 101^(st) to 144^(th) frames]. If a P-frame isgenerated from the 145^(th) frame, there will be an increase of 2 KBand, consequently, the 300 KB that can be received by the terminaldevice will be exceeded. Therefore, the first partitioned moving picturefile is generated using the 0^(th) to 144^(th) frames as one unit.

Since the 145^(th) frame becomes the leading frame of the nextpartitioned file, this frame is made an I-frame in such a manner thatone frame of a complete subject image is generated with just the145^(th) frame. The I-frame is again inserted every 50 frames using the145^(th) frame, which is the leading frame of the next partitioned file,as the reference. Similarly, the 145^(th), 195^(th) and 245^(th) framesare made I-frames and P-frames are inserted between these I-frames. Thetotal amount of data from the 145^(th) to the 289^(th) frames is 299 KB.The second partitioned moving picture file is generated using the145^(th) to 289^(th) frames as one unit.

Since the 290^(th) frame becomes the leading frame of the nextpartitioned file, this frame is made an I-frame. The I-frame is againinserted every 50 frames using the 290^(th) frame as the reference. The290^(th), 340^(th) and 390^(th) frames are made I-frames. The totalamount of data from the 290^(th) to the 411^(th) frames is 253 KB. Thethird partitioned moving picture file is generated using the 290^(th) to411^(th) frames as one unit.

Thus, in accordance with this embodiment, a moving picture file can bepartitioned into three portions.

FIG. 3 is a block diagram illustrating the electrical configuration of amoving picture compression apparatus 1.

The operation of the overall moving picture compression apparatus 1 iscontrolled by a CPU 5. The moving picture compression apparatus 1includes a main memory 7 for storing data, etc., and a memory controlunit 6 for controlling the main memory 7.

The moving picture compression apparatus 1 includes a terminalspecifications database 9. Specifications (maximum receivable amount ofdata, etc.) of a terminal device to which a transmission is to be madehave been stored in the terminal specifications database 9 for everyterminal device. The specifications data that has been stored in theterminal specifications database 9 is read by a transmissionspecifications acquisition unit 8.

Original moving picture data, which has not been compressed, is acquiredby an original moving picture acquisition unit 2. If the original movingpicture acquisition unit 2 is a communication unit, then theuncompressed moving picture data may be transmitted from anotherapparatus, or moving picture data that has been recorded on a digitalmedium such as a disk may be read. Moving picture data that has beenacquired by the original moving picture acquisition unit 2 is encoded(compressed) by a moving picture data encoder 3 in the manner describedabove. The amount of data encoded is calculated by a code-quantitycalculation unit 10, and the moving picture data (moving picture file)is partitioned in such a manner that the amount will fall below theamount of data capable of being received by the terminal device to whicha transmission is to be made. The partitioned moving picture data isstored in a transmission moving picture database 4.

If a terminal device issues a request for transmission of moving picturedata, partitioned moving picture data that has been stored in thetransmission moving picture database 4 is transmitted to this terminaldevice by a content distribution unit 11.

FIG. 4 is a flowchart illustrating processing executed by the movingpicture compression apparatus.

Original moving picture data is acquired (step 21), as set forth above.A number of frames of a subject image represented by the uncompressedoriginal moving picture data are input to the moving picture dataencoder 3 one frame at a time. A subject image of a frame of aprescribed ordinal number (the 50^(th) frame in the above-describedexample) from a reference frame (initially the 0^(th) frame) issubjected to spatial compression, whereby an I-frame is generated, andthe subject images in frames other than the frame of the prescribedordinal number are subjected to temporal processing, whereby P-framesare generated (step 22). The amount of code (amount of data) from thereference frame is accumulated (step 23).

If the accumulated value is equal to or greater than a threshold value(the amount of data capable of being received by the terminal device towhich a transmission is to be made) (“NO” at step 24), then the movingpicture data of the I-frames and P-frames generated thus far cannot bereceived by the transmission-target terminal device even if this data istransmitted to the transmission-target terminal device. Therefore, asmentioned above, with regard to the last frame, which is that in whichthe accumulated value has exceeded the threshold value owing toapplication of compression, this frame is made an I-frame, which is theleading frame of the next partitioned moving picture file, and serves asa reference frame. Frames up to the frame preceding the last framebecome the initial partitioned moving picture file. If 300 KB isexceeded owing to compression of the 145^(th) frame, frames up to the144^(th) frame become the first partitioned moving picture file and the145^(th) frame becomes the initial frame of the next moving picturefile, as illustrated in FIG. 2.

The I-frame at the beginning of the next partitioned moving picture fileis adopted as the reference frame (step 26), the accumulated value isreset and the processing of steps 22 to 26 is repeated until the finalframe of the original image is reached (step 27).

FIGS. 5 and 6 illustrate another embodiment of the present invention. Inthe above-described embodiment, partitioned moving picture files aregenerated with regard to one type of terminal device to which atransmission is to be made. In the embodiment illustrated next, however,partitioned moving picture files are generated with regard to two typesof terminal device to which a transmission is to be made.

FIG. 5 is a conceptual view of a moving picture that has beencompressed.

In a manner similar to that described above, it is assumed that theamount of data in an I-frame is 5 KB, the amount of data in a P-frame in2 KB, the maximum amount of data that can be received by a firstterminal device is 200 KB and the maximum amount of data that can bereceived by a second terminal device is 300 KB. In principle, an I-frameis inserted every 50 frames.

The amount of data in the 0^(th) frame is 5 KB, the amount of data fromthe 1^(st) frame to the 49^(th) frame is 98 KB, the amount of data inthe 50^(th) frame is 5 KB, and the amount of data from the 51^(st) tothe 96^(th) frames is 92 KB. The total amount of data from the 0^(th)frame to the 96^(th) frame is 200 KB. Since the maximum amount of datathat can be received by the first terminal device is 200 KB, the framesfrom the 0^(th) frame to the 96^(th) frame become the first partitionedmoving picture file for the first terminal device. The 97^(th) frame isadopted as an I-frame since it is the leading frame of the nextpartitioned moving picture file.

The amount of data in the 97^(th) frame is 5 KB and the amount of datafrom the 98^(th) frame to the 144^(th) frame is 94 KB. The total amountof data from the 0^(th) frame to the 144^(th) frame is 299 KB. Theframes from the 0^(th) frame to the 144^(th) frame become the firstpartitioned moving picture file for the second terminal device. The145^(th) frame is adopted as an I-frame since it is the leading frame ofthe next partitioned moving picture file.

Similarly, the total amounts of data from the 97^(th) frame to 193^(rd)frame, from the 194^(th) frame to the 289^(th) frame and from the290^(th) frame to the 386^(th) frame are each 200 KB, and these sets offrames become second, third and fourth partitioned moving picture files,respectively, for the first terminal device. The total amount of datafrom the 387^(th) frame to the 411^(th) frame is 53 KB, and these framesconstitute a fifth partitioned moving picture file. Thus, fivepartitioned moving picture files are generated as partitioned files forthe first terminal device.

Similarly, with regard to the second terminal device, the total amountof data from the 145^(th) frame to the 289^(th) frame is 299 KB andthese frames constitute the second partitioned moving picture file. Thetotal amount of data from the 290^(th) frame to the 411^(th) frame is253 KB and these frames constitute the third partitioned moving picturefile. Thus, three partitioned moving picture files are generated aspartitioned files for the second terminal device.

FIG. 6 is a flowchart illustrating processing executed by the movingpicture compression apparatus according to this embodiment. Processingsteps in FIG. 6 identical with those shown in FIG. 4 are designated bylike step numbers and need not be described again.

In the processing described above, a single threshold value is comparedwith the accumulated value (step 24 in FIG. 4). In this embodiment,however, two threshold values, namely the above-mentioned amount of datathat can be received by the first terminal device and the amount of datathat can be received by the second terminal device, are compared withthe accumulated value (step 24A). If the accumulated value is equal toor greater than either of these threshold values (“NO” at step 24A),then the last frame, which is that in which the accumulated value hasexceeded the threshold value owing to application of compression, ismade an I-frame (step 25), and frames up to the frame preceding the lastframe become the partitioned moving picture file.

In the foregoing embodiments, the amount of data in an I-frame isconsidered to be a uniform 5 KB and the amount of data in a P-frame isconsidered to be a uniform 2 KB in order to facilitate understanding ofthe present invention. However, it goes without saying that theseamounts of data need not necessarily be uniform. Further, the ratiobetween I-frames and P-frames may differ depending upon the movingpicture.

Furthermore, transmission is not limited to terminal devices of twotypes; a transmission may be made to three or more types of terminaldevices. In addition, the leading frame of a partitioned moving picturefile may be made an I-frame.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

What is claimed is:
 1. An apparatus comprising: a compressing device forexecuting complete compression processing if subject-image datarepresents a subject image of a frame of a prescribed ordinal numberfrom a reference frame, and for executing differential compressionprocessing if subject-image data does not represent a subject image of aframe of a prescribed ordinal number; an accumulating device foraccumulating an amount of data from the reference frame, wherein theamount of data is the amount of subject-image data that has undergonecomplete compression processing and differential compression processing;a determining device for determining whether an accumulated valueobtained from said accumulating device has exceeded a value calculatedfrom an amount of data receivable by a terminal device to which a movingpicture file is to be transmitted; and a control device, responsive to adetermination by said determination device, for controlling saidcompressing device in such a manner that complete compression processingis applied to subject-image data representing a subject image of a framethat has exceeded the receivable amount of data owing to execution ofcompression processing; wherein said determining device determineswhether the accumulated value obtained from said accumulating device hasexceeded a first amount of data receivable by a first terminal device towhich a moving picture file is to be transmitted, or a second amount ofdata receivable by a second terminal device to which a moving picturefile is to be transmitted; and said control device has: a first controldevice for controlling said compressing device in such a manner thatcomplete compression processing is applied to subject-image datarepresenting a subject image of a frame that has exceeded the firstreceivable amount of data owing to execution of compression processing;and a second control device for controlling said compressing device insuch a manner that complete compression processing is applied tosubject-image data representing a subject image of a frame that hasexceeded the second receivable amount of data owing to execution ofcompression processing; wherein the reference frame begins a firstpartition, the frame that has exceeded the first receivable amount ofdata begins a second partition, a last frame before the frame that hasexceeded the first receivable amount of data ends the first partition,and the first partition comprises more than one frame to which completecompression processing has been applied.
 2. The apparatus of claim 1,wherein the first partition and the second partition have equal numbersof frames.
 3. The apparatus of claim 1, wherein the first partition andthe second partition have non-equal numbers of frames.
 4. The apparatusof claim 1, wherein execution of the complete compression processing isassociated with an I frame.
 5. The apparatus of claim 1, whereinexecution of the differential compression processing is associated witha P frame.
 6. The apparatus of claim 1, wherein the first partitionincludes a first I frame and a second I frame associated with differentamounts of data.
 7. The apparatus of claim 1, wherein the firstpartition includes a first P frame and a second P frame associated withdifferent amounts of data.
 8. The apparatus of claim 1, furthercomprising a database including specifications regarding the firstreceivable amount of data of the first terminal device to which themoving picture file is to be transmitted and the second receivableamount of data of the second terminal device to which the moving picturefile is to be transmitted.
 9. The apparatus of claim 1, wherein thefirst terminal device and the second terminal device are associated withdifferent terminal device types.
 10. The apparatus of claim 1, whereinthe first terminal device is configured to transmit the moving picturefile.
 11. A computer implemented method comprising: executing, by acompressing device, complete compression processing if subject-imagedata represents a subject image of a frame of a prescribed ordinalnumber from a reference frame, and executing, by the compressing device,differential compression processing if subject-image data does notrepresent a subject image of a frame of a prescribed ordinal number;accumulating, by an accumulating device, an amount of data from thereference frame, wherein the amount of data is the amount ofsubject-image data that has undergone complete compression processingand differential compression processing; determining, by a determiningdevice, whether an accumulated value obtained from said accumulatingdevice has exceeded a value calculated from an amount of data receivableby a terminal device to which a moving picture file is to betransmitted; and in response to a determination by said determinationdevice, controlling said compressing device in such a manner thatcomplete compression processing is applied to subject-image datarepresenting a subject image of a frame that has exceeded the receivableamount of data owing to execution of compression processing; whereinsaid determining comprises determining whether the accumulated valueobtained from said accumulating device has exceeded a first amount ofdata receivable by a first terminal device to which a moving picturefile is to be transmitted, or a second amount of data receivable by asecond terminal device to which a moving picture file is to betransmitted; and wherein said controlling comprises: controlling, by afirst control device, said compressing device in such a manner thatcomplete compression processing is applied to subject-image datarepresenting a subject image of a frame that has exceeded the firstreceivable amount of data owing to execution of compression processing;and controlling, by a second control device, said compressing device insuch a manner that complete compression processing is applied tosubject-image data representing a subject image of a frame that hasexceeded the second receivable amount of data owing to execution ofcompression processing; wherein the reference frame begins a firstpartition, the frame that has exceeded the first receivable amount ofdata begins a second partition, a last frame before the frame that hasexceeded the first receivable amount of data ends the first partition,and the first partition comprises more than one frame to which completecompression processing has been applied.
 12. The method of claim 11,further comprising: transmitting the first partition and the secondpartition to the first terminal device.
 13. The method of claim 11,further comprising: accessing a database to determine the firstreceivable amount of data of the first terminal device and the secondreceivable amount of data of the second terminal device.
 14. The methodof claim 11, wherein the first partition and the second partition havenon-equal numbers of frames.
 15. The method of claim 11, wherein thefirst partition includes a first I frame and a second I frame associatedwith different amounts of data.
 16. The method of claim 11, whereinexecution of the complete compression processing is associated with an Iframe.
 17. A non-transitory computer storage medium storingcomputer-executable instructions that, when executed, cause a computersystem to perform a computer-implemented method comprising: executingcomplete compression processing if subject-image data represents asubject image of a frame of a prescribed ordinal number from a referenceframe, and executing, by the compressing device, differentialcompression processing if subject-image data does not represent asubject image of a frame of a prescribed ordinal number; accumulating anamount of data from the reference frame, wherein the amount of data isthe amount of subject-image data that has undergone complete compressionprocessing and differential compression processing; determining whetheran accumulated value obtained from said accumulating device has exceededa value calculated from an amount of data receivable by a terminaldevice to which a moving picture file is to be transmitted; and inresponse to a determination by said determination device, controllingsaid compressing device in such a manner that complete compressionprocessing is applied to subject-image data representing a subject imageof a frame that has exceeded the receivable amount of data owing toexecution of compression processing; wherein said determining comprisesdetermining whether the accumulated value obtained from saidaccumulating device has exceeded a first amount of data receivable by afirst terminal device to which a moving picture file is to betransmitted, or a second amount of data receivable by a second terminaldevice to which a moving picture file is to be transmitted; and whereinsaid controlling comprises: controlling said compressing device in sucha manner that complete compression processing is applied tosubject-image data representing a subject image of a frame that hasexceeded the first receivable amount of data owing to execution ofcompression processing; and controlling said compressing device in sucha manner that complete compression processing is applied tosubject-image data representing a subject image of a frame that hasexceeded the second receivable amount of data owing to execution ofcompression processing; wherein the reference frame begins a firstpartition, the frame that has exceeded the first receivable amount ofdata begins a second partition, a last frame before the frame that hasexceeded the first receivable amount of data ends the first partition,and the first partition comprises more than one frame to which completecompression processing has been applied.
 18. The non-transitory computerstorage medium of claim 17, wherein the computer-implemented methodfurther comprises accessing a database to determine the first receivableamount of data of the first terminal device and the second receivableamount of data of the second terminal device.
 19. The non-transitorycomputer storage medium of claim 17, wherein the first partitionincludes a first I frame and a second I frame associated with differentamounts of data.
 20. The non-transitory computer storage medium of claim17, wherein execution of the complete compression processing isassociated with an I frame.